A number of document handling devices are known in the art for sorting and stacking documents, paper and/or printable media. One document handling device comprises a printer, such as a laser or an inkjet printer. Another document handling device comprises a copy machine. Yet another document handling device comprises a facsimile machine. Even another document handling device comprises a document scanning device. With each of these devices, stacks of documents are processed by the device to generate output jobs such as print jobs or facsimile output jobs. To aid in identifying individual output jobs, a number of techniques have been employed when delivering individual jobs to an output tray of a document handling device.
Several techniques have been employed to identify individual jobs when they are deposited in an output tray of a document handling device. For example, it has long been known to generate special header sheets at the beginning of each new print job of a printer or a copy machine. In the past, a header sheet has been formed from a piece of paper sized identically to the pages of the output job. The header sheet typically has hash marks extending around the outer border so as to visually identify the sheet as a header sheet, and contains additional identifying information such as a user identification or a job identification number. However, it is oftentimes difficult to identify a header sheet from within a stack of print jobs as they are formed from identically sized pieces of paper.
Another technique for identifying jobs within an output tray of a document handling device entails stacking together the sheets of paper forming a job in offset positions, such that each job is offset from neighboring jobs. For example, it is known to sort sheets of paper on a tray such that individual jobs are offset by either repositioning the output or discharge rollers during paper delivery/output so as to deliver successive print jobs that are offset from adjacent print jobs. Optionally, it is known to laterally reposition an output tray between neighboring print jobs such that adjacent print jobs will be offset from one another. Exemplary details of such offset stacking arrangements are shown below in greater detail with reference to FIG. 4. One problem associated with the offset stacking of print jobs is encountered by users who are unfamiliar with such offset stacking. It is relatively easy and common for a user to retrieve a plurality of adjacent, offset print jobs from an output tray, then collect the jobs together by edgewise inverting the stack of jobs in a vertical configuration, and dropping the stack of loosely held jobs onto the edge of a tabletop so as to align all the jobs into a single, neat pile. The above typically occurs because a user is simply unaware that the stack of offset print job has been generated in this manner so as to separate individual jobs to facilitate retrieval of individual jobs from an output stack. Such frequent occurrence has led many copier manufacturers and printer manufacturers to eliminate offset delivery features from their devices. To many users, it is relatively unclear that such offset delivery is intended to separate print jobs. In the case of many users, the user merely feels that they are re-stacking a poorly stacked collection of print jobs. Therefore, there is a need to provide an improved way for identifying job separation and for implementing a job separation process.
Another technique that allows a limited amount of identification between jobs delivered to an output tray on a document handling device is provided by devices that have more than one input source for delivering paper to the device. For example, most printers have at least two standard input sources, such as a multipurpose tray and a standard-sized tray. One tray can be configured to provide 81/2.times.11 inch paper, and another tray can be configured to provide A4 paper or legal-sized paper. Accordingly, a printer is able to print on different paper sizes such as letter-sized, legal-sized, ledger-sized, A4-sized, etc. It is also very common to provide at least two output trays for receiving jobs, or media, which have been processed by the printer. For example, print jobs comprising printed media can be delivered either to a face-up tray that is provided at the rearmost end of many printers, or to a face-down tray that is most often located at the top of a printer. A limited capability for distinguishing individual print jobs can be provided by printing adjacent print jobs on different sized paper. However, it is unlikely that adjacent print jobs will require different sized paper. Additionally, it is inconvenient and undesirable to print successive print jobs on different sized paper when most users require the use of a standard sized, or commonly sized, paper when printing a job.